hlo_verifier.h

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/* Copyright 2017 The TensorFlow Authors. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/
#ifndef TENSORFLOW_COMPILER_XLA_SERVICE_HLO_VERIFIER_H_
#define TENSORFLOW_COMPILER_XLA_SERVICE_HLO_VERIFIER_H_
#include "tensorflow/compiler/xla/service/hlo_pass_interface.h"
#include "tensorflow/compiler/xla/service/shape_inference.h"
namespace xla {
// Visitor which verifies that the output shape is correctly set. Verifies
// against the inferred shape for the instruction.
// TODO(b/26024837): Check output shape for all instruction types.
class ShapeVerifier : public DfsHloVisitor {
 public:
  explicit ShapeVerifier() : allow_mixed_precision_(false) {}
  explicit ShapeVerifier(bool allow_mixed_precision)
      : allow_mixed_precision_(allow_mixed_precision) {}
  Status HandleElementwiseUnary(HloInstruction* hlo) override;
  Status HandleElementwiseBinary(HloInstruction* hlo) override;
  Status HandleClamp(HloInstruction* clamp) override;
  Status HandleSelect(HloInstruction* select) override;
  Status HandleConcatenate(HloInstruction* concatenate) override;
  Status HandleConvert(HloInstruction* convert) override;
  Status HandleBitcastConvert(HloInstruction* convert) override;
  Status HandleCopy(HloInstruction* copy) override;
  Status HandleDot(HloInstruction* dot) override;
  Status HandleConvolution(HloInstruction* convolution) override;
  Status HandleFft(HloInstruction* fft) override;
  Status HandleCrossReplicaSum(HloInstruction* crs) override;
  Status HandleReducePrecision(HloInstruction* reduce_precision) override;
  Status HandleInfeed(HloInstruction*) override;
  Status HandleOutfeed(HloInstruction*) override;
  Status HandleRng(HloInstruction*) override;
  Status HandleReverse(HloInstruction* reverse) override;
  Status HandleSort(HloInstruction* sort) override;
  Status HandleConstant(HloInstruction* constant) override;
  Status HandleGetTupleElement(HloInstruction* get_tuple_element) override;
  Status HandleReduce(HloInstruction* reduce) override;
  Status HandleBitcast(HloInstruction* bitcast) override;
  Status HandleBroadcast(HloInstruction* broadcast) override;
  Status HandleBroadcastDimOne(HloInstruction* broadcastDimOne) override;
  Status HandleReshape(HloInstruction* reshape) override;
  Status HandleTranspose(HloInstruction* transpose) override;
  Status HandleParameter(HloInstruction*) override;
  Status HandleFusion(HloInstruction*) override;
  Status HandleCall(HloInstruction* call) override;
  Status HandleCustomCall(HloInstruction*) override;
  Status HandleHostCompute(HloInstruction*) override;
  Status HandleSlice(HloInstruction* slice) override;
  Status HandleDynamicSlice(HloInstruction* dynamic_slice) override;
  Status HandleDynamicUpdateSlice(
      HloInstruction* dynamic_update_slice) override;
  Status HandleTuple(HloInstruction* tuple) override;
  Status HandleMap(HloInstruction* map) override;
  Status HandleReduceWindow(HloInstruction* reduce_window) override;
  Status HandleSelectAndScatter(HloInstruction* instruction) override;
  Status HandleWhile(HloInstruction* xla_while) override;
  Status HandleConditional(HloInstruction* conditional) override;
  Status HandlePad(HloInstruction* pad) override;
  Status HandleSend(HloInstruction* send) override;
  Status HandleSendDone(HloInstruction* send_done) override;
  Status HandleRecv(HloInstruction* recv) override;
  Status HandleRecvDone(HloInstruction* recv_done) override;
  Status HandleBatchNormTraining(HloInstruction* batch_norm_training) override;
  Status HandleBatchNormInference(
      HloInstruction* batch_norm_inference) override;
  Status HandleBatchNormGrad(HloInstruction* batch_norm_grad) override;
  Status HandleGather(HloInstruction* gather) override;
  Status FinishVisit(HloInstruction*) override {
    return tensorflow::Status::OK();
  }
 protected:
  // Check the instruction's shape against the shape given by ShapeInference
  // and return an appropriate error if there is a mismatch.
  Status CheckShape(const HloInstruction* instruction,
                    const Shape& inferred_shape);
  // Overload which takes a StatusOr to reduce boilerplate in the caller.
  Status CheckShape(const HloInstruction* instruction,
                    const StatusOr<Shape>& inferred_shape_status);
  // Check a unary (binary, etc) instruction's shape against the inferred shape.
  Status CheckUnaryShape(const HloInstruction* instruction);
  Status CheckBinaryShape(const HloInstruction* instruction);
  Status CheckTernaryShape(const HloInstruction* instruction);
  Status CheckVariadicShape(const HloInstruction* instruction);
  // Checks if the given two instructions shares the same channel id.
  Status CheckSameChannel(const HloInstruction* instr1,
                          const HloInstruction* instr2);
 private:
  // Whether the inputs and output of an instruction can contain both F32s and
  // BF16s. Tuples that include both F32s and BF16s are allowed regardless of
  // this flag.
  bool allow_mixed_precision_;
};
class HloVerifier : public HloPassInterface {
 public:
  using ShapeVerifierFactory = std::function<std::unique_ptr<ShapeVerifier>()>;
  // Uses standard shape inference.
  explicit HloVerifier()
      : shape_verifier_factory_(
            [] { return MakeUnique<ShapeVerifier>(false); }) {}
  explicit HloVerifier(bool allow_mixed_precision)
      : shape_verifier_factory_([allow_mixed_precision] {
          return MakeUnique<ShapeVerifier>(allow_mixed_precision);
        }) {}
  // Uses custom shape verification.
  explicit HloVerifier(ShapeVerifierFactory shape_verifier_factory)
      : shape_verifier_factory_(std::move(shape_verifier_factory)) {}
  ~HloVerifier() override = default;
  tensorflow::StringPiece name() const override { return "verifier"; }
  // Note: always returns false (no instructions are ever modified by this
  // pass).
  StatusOr<bool> Run(HloModule* module) override;
 private:
  // CHECKs various invariants of a fusion instruction.
  Status CheckFusionInstruction(HloInstruction* fusion) const;
  // Creates a ShapeVerifier that checks that shapes match inferred
  // expectations.  This is a factory function because ShapeVerifier,  Note that
  // ShapeVerifier, being a DfsHloVisitor, is stateful.  We want a clean object
  // for each run of the verifier.
  ShapeVerifierFactory shape_verifier_factory_;
};
}  // namespace xla
#endif  // TENSORFLOW_COMPILER_XLA_SERVICE_HLO_VERIFIER_H_